Which year saw the withdrawal of the last British troops from Malta?

Malta officially, known as the Republic of Malta, is a Southern European island country consisting of an archipelago in the Mediterranean Sea. It lies 80 km (50 mi) south of Italy, 284 km (176 mi) east of Tunisia, and 333 km (207 mi) north of Libya. With a population of about 475,000 over an area of 316 km2 (122 sq mi), Malta is the world's tenth smallest and fifth most densely populated country. Its capital is Valletta, which is the smallest national capital in the European Union by area at 0.8 km². The official languages are Maltese and English, with Maltese officially recognised as the national language and the only Semitic language in the European Union.

Malta became independent on 21 September 1964 (Independence Day). Under its 1964 constitution, Malta initially retained Queen Elizabeth II as Queen of Malta, with a Governor-General exercising executive authority on her behalf. On 13 December 1974, (Republic Day) it became a republic within the Commonwealth, with the President as head of state. On 31 March 1979, Malta saw the withdrawal of the last British troops and the Royal Navy from Malta. This day is known as Freedom Day and Malta declared itself as a neutral and non-aligned state. Malta joined the European Union on 1 May 2004 and joined the Eurozone on 1 January 2008.